Fix #81 by checking for air or unregistered block

[BlueAgent]

Fix #81 by adding a check for air or unregistered block.

[21Feb2021 13:27:33.651] [Worker-Main-14/INFO] [powah/Config]: Added block: minecraft:lava, with heat of: 1000
[21Feb2021 13:27:33.651] [Worker-Main-14/INFO] [powah/Config]: Added block: minecraft:magma_block, with heat of: 1200
[21Feb2021 13:27:33.651] [Worker-Main-14/INFO] [powah/Config]: Added block: minecraft:fire_coral, with heat of: 1800
[21Feb2021 13:27:33.651] [Worker-Main-14/INFO] [powah/Config]: Added block: powah:nitro_crystal_block, with heat of: 8000
[21Feb2021 13:27:33.652] [Worker-Main-14/INFO] [powah/Config]: Added block: powah:blazing_crystal_block, with heat of: 2800
[21Feb2021 13:27:33.652] [Worker-Main-14/INFO] [powah/Config]: Added block: botania:blaze_block, with heat of: 1600
[21Feb2021 13:27:33.652] [Worker-Main-14/FATAL] [powah/Config]: Ignored air or unregistered block registry name botania:blaze_lantern.
[21Feb2021 13:27:33.652] [Worker-Main-14/INFO] [powah/Config]: Added block: quark:brimstone, with heat of: 1200
[21Feb2021 13:27:33.652] [Worker-Main-14/INFO] [powah/Config]: Added fluid: minecraft:lava, with heat of: 10000 per 100 mb

[owmii]

Thank you!!